Image/forming apparatus including an organic substance at low pressure

Abstract

An image-forming apparatus includes an electron source including one or more than one electron-emitting devices on a substrate, each electron-emitting device having a pair of oppositely disposed device electrodes, an electroconductive film connected to the pair of device electrodes and an electron-emitting region formed in part of the electroconductive film accompanied by a carbonaceous film which contains carbon or carbon compound as principal ingredient and is formed on and in a vicinity of the electron-emitting region, and an image-forming member for forming an image by emitting light when irradiated with electron beams emitted from the electron source. The electron source and the image-forming member are contained in a vacuum envelope, and an organic substance exists in the vacuum envelope to show a partial pressure of the organic substance greater than 1×10 -6 Pa and a total pressure lower than 1×10 -3 Pa. The organic substance is so selected that it shows a mean absorption time shorter than the drive period of the electron source.

What is claimed is: 
     
       1. An image-forming apparatus comprising an electron source including one or more than one electron-emitting devices on a substrate, each electron-emitting device having a pair of oppositely disposed device electrodes, an electroconductive film connected to the pair of device electrodes and an electron-emitting region formed in part of the electroconductive film accompanied by a carbonaceous film which contains carbon or carbon compound as principal ingredient and is formed on and in a vicinity of the electron-emitting region, and an image-forming member for forming an image by emitting light when irradiated with electron beams emitted from the electron source, the electron source and the image-forming member being contained in a vacuum envelope, characterized in that an organic substance exists in the vacuum envelope to show a partial pressure of the organic substance greater than 1×10 -6  Pa and a total pressure lower than 1×10 -3  Pa, the organic substance being so selected that it shows a mean absorption time shorter than the drive period of the electron source. 
     
     
       2. An image-forming apparatus according to claim 1, characterized in that the partial pressure of the organic substance is not lower than 1×10 -4  Pa. 
     
     
       3. An image-forming apparatus according to claim 1, wherein hydrogen gas exists in the vacuum envelope in addition to the organic substance. 
     
     
       4. An image-forming apparatus according to any of claims 1 through 3, characterized in that the organic substance is CH 4  (methane), C 2  H 4  (ethylene), C 2  H 2  (acetylene) or C 4  H 2  (butadiyne). 
     
     
       5. A method of manufacturing an image-forming apparatus comprising an electron source including one or more than one electron-emitting devices on a substrate, each electron-emitting device having a pair of oppositely disposed device electrodes, an electroconductive film connected to the pair of device electrodes and an electron-emitting region formed in part of the electroconductive film accompanied by a carbonaceous film which contains carbon or carbon compound as principal ingredient and is formed on and in a vicinity of the electron-emitting region, and an image-forming member for forming an image by emitting light when irradiated with electron beams emitted from the electron source, the electron source and the image-forming member being contained in a vacuum envelope, characterized in that it comprises an energization forming step for producing said electron-emitting regions, an activation step for forming said carbonaceous films containing carbon or carbon compound as principal ingredient by deposition on and in a vicinity of the electron-emitting region of each of the electron-emitting devices by introducing an organic substance into the vacuum envelope and applying a pulse voltage to the device, a stabilization step for removing the organic substance remaining in the vacuum envelope after the end of the activation step and a gas feeding step for introducing an organic substance having a mean absorption time shorter than the drive period of the electron-emitting devices or a mixture gas of the organic substance and hydrogen gas, the partial pressure of the organic substance having a mean absorption time longer than the drive period of the electron-emitting devices being held not greater than 1.0×10 6  Pa. 
     
     
       6. A method of manufacturing an image-forming apparatus according to claim 5, characterized in that the internal pressure of the vacuum envelope is held not greater than 1.0×10 -6  Pa in the stabilization step. 
     
     
       7. A method of manufacturing an image-forming apparatus according to claim 5, characterized in that the organic substance introduced into the vacuum envelope in the activation step is same as the organic substance introduced in the gas feeding step. 
     
     
       8. A method of manufacturing an image-forming apparatus according to claim 5, characterized in that the organic substance having a mean absorption time shorter than the drive period of the electron-emitting devices is CH 4  (methane), C 2  H 4  (ethylene), C 2  H 2  (acetylene) or C 4  H 2  (butadiyne). 
     
     
       9. An electron emission apparatus comprising: a) a sealed envelope containing therein an electron-emitting device, said electron-emitting device having a carbonaceous film comprising carbon or a carbon compound; and   b) voltage application means for applying a voltage to said electron-emitting device at an interval greater than 3.57×10 -7  sec, wherein   said sealed envelope has an inner atmosphere showing a total pressure lower than 1×10 -3  Pa,   said inner atmosphere comprises an organic substance selected from methane, ethylene or acetylene, and   said organic substance shows a partial pressure higher than 1×10 -6  Pa.   
     
     
       10. An electron emission apparatus according to claim 9, wherein said inner atmosphere further comprises hydrogen. 
     
     
       11. An electron emission apparatus according to claim 9, wherein said interval is greater than 16 msec. 
     
     
       12. An electron emission apparatus according to claim 9, wherein said apparatus further comprises an acceleration electrode for accelerating electrons emitted from said electron-emitting device. 
     
     
       13. An electron emission apparatus according to claim 12, wherein a fluorescent body is arranged on said acceleration electrode. 
     
     
       14. An electron emission apparatus according to claim 13, wherein said fluorescent body emits light of the three primary colors by irradiation with electrons emitted from said electron-emitting device. 
     
     
       15. An electron emission apparatus according to claim 9, wherein said electron-emitting device further comprises an electroconductive film having a gap, and said carbonaceous film is arranged on said electroconductive film. 
     
     
       16. An electron emission apparatus according to claim 9, wherein said electron-emitting device further comprises a pair of electroconductive films oppositely disposed with a gap interposed therebetween and said carbonaceous film is arranged on said pair of electroconductive films. 
     
     
       17. An electron emission apparatus according to claim 9, wherein said carbonaceous film comprises a pair of carbonaceous films oppositely disposed with a first gap interposed therebetween. 
     
     
       18. An electron emission apparatus according to claim 17, wherein said electron-emitting device further comprises an electroconductive film having a second gap, and said pair of carbonaceous films are arranged on said electroconductive film. 
     
     
       19. An electron emission apparatus according to claim 17, wherein said electron-emitting device further comprises a pair of electroconductive films oppositely disposed with a second gap interposed therebetween, and said pair of carbonaceous films are arranged on said pair of electroconductive films. 
     
     
       20. An electron emission apparatus according to claim 18 or 19, wherein said first gap has a shorter distance than said second gap, and said first gap is located in said second gap. 
     
     
       21. An electron emission apparatus according to claim 9, wherein said sealed envelope contains therein a plurality of electron-emitting devices. 
     
     
       22. An electron emission apparatus according to claim 21, wherein said plurality of electron-emitting devices are connected to a plurality of row-directional wires and to a plurality of column-directional wires generally perpendicular to said row-directional wires. 
     
     
       23. An electron emission apparatus according to claim 21 or 22, wherein said apparatus further comprises an acceleration electrode for accelerating electrons emitted from said electron-emitting devices and a fluorescent body arranged on said acceleration electrode. 
     
     
       24. A method of manufacturing an electron emission apparatus, comprising steps of: a) arranging an electron-emitting device in an envelope, said electron-emitting device having a carbonaceous film comprising carbon or a carbon compound;   b) evacuating said envelope to have a partial pressure of organic substances therein become lower than 1.3×10 -6  Pa;   c) introducing into said envelope an organic substance selected from methane, ethylene or acetylene to have a partial pressure of said organic substance become higher than 1×10 -6  Pa; and   d) electrically connecting said electron-emitting device to a voltage application means for applying a voltage at an interval greater than 3.57×10 -7  sec.